Angularly disposed water-cooled skid rails



Aug. 22, 1967 G. B. KIRKPATRICK 3,337,199

ANGULARLY DISPOSE'D, WATER-COOLED SKID RAILS 7 Filed July 14. 1965 INVENTOR George B. Kirkpatrick United States Patent 3,337,199 ANGULARLY DISPOSED WATER-COOLED SKID RAILS George B. Kirkpatrick, 710 Delafield Road, Pittsburgh, Pa. 15215 Filed July 14, 1965, Ser. No. 471,939 3 Claims. (Cl. 266-5) This invention relates to skid devices and more particularly to a skid device for a slab heating furnace.

In a slab heating furnace the slab is forced from a charge end of the furnace to the discharge end of the furnace by pushing slabs edge to edge over water-cooled skid pipes. The slab discharge temperatures are not uniform. The reason for this is that skid marks or skid shadows are formed Where the slab comes in continual contact with the water-cooled skid pipes. The slab in contact with the cooled skid pipe does not receive the full benefit of the heat from the burners and forms a shadow or skid mark along the bottom of the slab. The temperature differential between the contact point of the bottom of the slab with the skid .pipe and the top of the slab causes variations in thickness of the final strip. The skid pipes with skid bars running on top of the entire length of the skid pipe are spaced in parallel relationship with the furnace sides. To overcome the problem created by shadow marks, an additional zone is provided at the discharge end called the soak zone. The soak zone, however, fails to equalize the temperatures from end to end of the slab and introduces a new differential of temperature from top to bottom. The problem becomes more acute as the slab thickness increases and uniform temperatures cannot be restored in a practical time. Also, if the slab is held on the soaking hearth long enough to eliminate any traces of lateral temperature differences resulting from skid shadows, a very undesirable vertical temperature difference would result. Other techniques advanced included providing fewer skid pipes which converge at one end of the furnace. The difficulty with this solution is that the slab does not move freely across the skid device. The

present invention eliminates the skid marks thereby limiting their need for a soak zone without impeding the movement of the slab across the skids.

I provide a skid device for continuous slab heating furnace which comprises a plurality of cooled skid pipes angularly disposed with respect to the longitudinal center of the furnace, the skid pipe spaced apart in parallel relationship with respect to each other, a plurality of skid bars mounted in longitudinal spaced relationship on each skid pipe, each skid bar angularly disposed across the top and around the skid pipe approximately 180, the skid bars parallel with the longitudinal sides of the furnace and a plurality of cooled skid pipe supports perpendicular to the longitudinal sides of the furnace, the skid pipe rests on top of the supports.

It is to be understood that the water cooled skid pipes can be supported within the refractories of an open hearth furnace.

Other details, objects and advantages of the invention will become apparent as the following description of a present preferred embodiment and a present preferred method of practicing the same proceeds.

In the accompanying drawings I have shown a present preferred embodiment of the invention and have illus ICC trated a present preferred method of practicing the same in which FIGURE 1 is a plan view of the slab heating furnace;

FIGURE 2 is a fragmentary enlarged view of one skid pipe; and

FIGURE 3 is a cross-sectional view of one skid pipe taken on the line III-III of FIGURE 2.

FIGURE 1 shows charging end 10 of a slab heating furnace 12. Water-cooled skid pipe supports 14 are spaced in parallel relationship to each other and are connected perpendicularly to the walls 16 of the slab heating fur nace 12. Water-cooled skid pipes 18 are parallel with respect to each other but are angularly or diagonally disposed with respect to the centerline of the slab heating furnace 12. Skid bars 20 are mounted angularly across skid pipes 18. The skid bars 20 are spaced longitudinally apart on top of each water-cooled skid pipe 18. The skid bars 20 all run parallel to the centerline and the walls 16 of the slab heating furnace 12. As slab 22 is pushed from the charging end 10 to the discharging end 24, it rides on the skid bars 20. Any one point on the bottom of the slab 22 engages the slab for only a minute distance and time. This is due to the angular relationship and spacing of the skid bars 20. The skid bars 20 are parallel to the walls 16 of the slab heating furnace 12 to enable free sliding movement of the slab 10. This pattern of skid bars 20 and cooled skid pipe 18 eliminates shadow marks and thereby limits the need for a soaking hearth.

FIGURES 2 and 3 show the skid bar 20 substantially wrapped around the skid pipe 18. This produces better cooling in the skid pipe and freer movement of the slab.

While I have shown and described a present preferred embodiment and have illustrated a present preferred method of practicing the same, it is to be distinctly understood that the invention is not limited thereto but may be variously embodied within the scope of the following claims.

I claim:

1. A skid device for continuous slab heating furnace which comprises:

(1) a plurality of skid pipes angularly disposed with respect to the longitudinal center of the furnace, the skid pipe spaced apart in parallel relationship with respect to each other; and

(2) a plurality of skid bars mounted in spaced relationship on top of each skid pipe, each skid bar is angularly disposed across the top of the skid pipe and parallel with the longitudinal sides of the furnace, the moving slab slides over the skid bar which directs it along the longitudinal center of the furnace.

2. A skid device for continuous slab heating furnace which comprises:

(1) a plurality of cooled skid pipes angularly disposed with respect to the longitudinal center of the furnace, the skid pipe spaced apart in parallel relationship with respect to each other;

(2) a plurality of skid bars mounted in longitudinal spaced relationship on top of each skid pipe, each skid bar angularly disposed across the top of the skid pipe and parallel with the longitudinal sides of the furnace; and

(3) a plurality of cooled skid pipe supports perpendicular to the longitudinal sides of the furnace, the skid pipe rests on top of the supports.

Patented Aug.22, 1967 3 4 3. A skid device for continuous slab heating furnace ular to the longitudinal sides of the furnace, the which comprises: skid pipe rests on top of the supports.

(1) a plurality of cooled skid pipe angularly disposed with respect to the longitudinal center of the furnace, References Cited the skid pipe spaced apart in parallel relationship 5 UNITED STATES PATENTS with res ect to each other; 2 a plu ality or skid bars mounted in longitudinal 2922549 12/1935 Cornsten 263-6 spaced relationship on top of each skid pipe, each 3168297 2/1965 Brough 263 6 skid bar angularly disposed across the top and around 3179395 4/1965 Esler 263 6 X the skid pipe 180, theskid bars parallel With the longitudinal Sides of the furnace; and 10 I. SPENCER OVERHOLSER, Primary Exammer.

(3) a plurality of cooled skid pipe supports perpendicn E. MAR, Assistant Examiner. 

1. A SKID DEVICE FOR CONTINUOUS SLAB HEATING FURNACE WHICH COMPRISES: (1) A PLURALITY OF SKID PIPES ANGULARLY DISPOSED WITH RESPECT TO THE LONGITUDINAL CENTER OF THE FURNACE, THE SKID PIPE SPACED APART IN PARALLEL RELATIONSHIP WITH RESPECT TO EACH OTHER; AND (2) A PLURALITY OF SKID BARS MOUNTED IN SPACED RELATIONSHIP ON TOP OF EACH SKID PIPE, EACH SKID BAR IS ANGULARLY DISPOSED ACROSS THE TOP OF THE SKID PIPE AND PARALLEL WITH THE LONGITUDINAL SIDES OF THE FURNACE, THE MOVING SLAB SLIDES OVER THE SKID BAR WHICH DIRECTS IT ALONG THE LONGITUDINAL CENTER OF THE FURNACE. 